// MIT License

// Copyright (c) 2019 Erin Catto

// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#include "test.h"

// This is a test of collision filtering.
// There is a triangle, a box, and a circle.
// There are 6 shapes. 3 large and 3 small.
// The 3 small ones always collide.
// The 3 large ones never collide.
// The boxes don't collide with triangles (except if both are small).
const int16 k_smallGroup = 1;
const int16 k_largeGroup = -1;

const uint16 k_triangleCategory = 0x0002;
const uint16 k_boxCategory      = 0x0004;
const uint16 k_circleCategory   = 0x0008;

const uint16 k_triangleMask = 0xFFFF;
const uint16 k_boxMask      = 0xFFFF ^ k_triangleCategory;
const uint16 k_circleMask   = 0xFFFF;

class CollisionFiltering : public Test
{
public:
    CollisionFiltering()
    {
        // Ground body
        {
            b2EdgeShape shape;
            shape.SetTwoSided(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));

            b2FixtureDef sd;
            sd.shape    = &shape;
            sd.friction = 0.3f;

            b2BodyDef bd;
            b2Body* ground = m_world->CreateBody(&bd);
            ground->CreateFixture(&sd);
        }

        // Small triangle
        b2Vec2 vertices[3];
        vertices[0].Set(-1.0f, 0.0f);
        vertices[1].Set(1.0f, 0.0f);
        vertices[2].Set(0.0f, 2.0f);
        b2PolygonShape polygon;
        polygon.Set(vertices, 3);

        b2FixtureDef triangleShapeDef;
        triangleShapeDef.shape   = &polygon;
        triangleShapeDef.density = 1.0f;

        triangleShapeDef.filter.groupIndex   = k_smallGroup;
        triangleShapeDef.filter.categoryBits = k_triangleCategory;
        triangleShapeDef.filter.maskBits     = k_triangleMask;

        b2BodyDef triangleBodyDef;
        triangleBodyDef.type = b2_dynamicBody;
        triangleBodyDef.position.Set(-5.0f, 2.0f);

        b2Body* body1 = m_world->CreateBody(&triangleBodyDef);
        body1->CreateFixture(&triangleShapeDef);

        // Large triangle (recycle definitions)
        vertices[0] *= 2.0f;
        vertices[1] *= 2.0f;
        vertices[2] *= 2.0f;
        polygon.Set(vertices, 3);
        triangleShapeDef.filter.groupIndex = k_largeGroup;
        triangleBodyDef.position.Set(-5.0f, 6.0f);
        triangleBodyDef.fixedRotation = true;  // look at me!

        b2Body* body2 = m_world->CreateBody(&triangleBodyDef);
        body2->CreateFixture(&triangleShapeDef);

        {
            b2BodyDef bd;
            bd.type = b2_dynamicBody;
            bd.position.Set(-5.0f, 10.0f);
            b2Body* body = m_world->CreateBody(&bd);

            b2PolygonShape p;
            p.SetAsBox(0.5f, 1.0f);
            body->CreateFixture(&p, 1.0f);

            b2PrismaticJointDef jd;
            jd.bodyA       = body2;
            jd.bodyB       = body;
            jd.enableLimit = true;
            jd.localAnchorA.Set(0.0f, 4.0f);
            jd.localAnchorB.SetZero();
            jd.localAxisA.Set(0.0f, 1.0f);
            jd.lowerTranslation = -1.0f;
            jd.upperTranslation = 1.0f;

            m_world->CreateJoint(&jd);
        }

        // Small box
        polygon.SetAsBox(1.0f, 0.5f);
        b2FixtureDef boxShapeDef;
        boxShapeDef.shape       = &polygon;
        boxShapeDef.density     = 1.0f;
        boxShapeDef.restitution = 0.1f;

        boxShapeDef.filter.groupIndex   = k_smallGroup;
        boxShapeDef.filter.categoryBits = k_boxCategory;
        boxShapeDef.filter.maskBits     = k_boxMask;

        b2BodyDef boxBodyDef;
        boxBodyDef.type = b2_dynamicBody;
        boxBodyDef.position.Set(0.0f, 2.0f);

        b2Body* body3 = m_world->CreateBody(&boxBodyDef);
        body3->CreateFixture(&boxShapeDef);

        // Large box (recycle definitions)
        polygon.SetAsBox(2.0f, 1.0f);
        boxShapeDef.filter.groupIndex = k_largeGroup;
        boxBodyDef.position.Set(0.0f, 6.0f);

        b2Body* body4 = m_world->CreateBody(&boxBodyDef);
        body4->CreateFixture(&boxShapeDef);

        // Small circle
        b2CircleShape circle;
        circle.m_radius = 1.0f;

        b2FixtureDef circleShapeDef;
        circleShapeDef.shape   = &circle;
        circleShapeDef.density = 1.0f;

        circleShapeDef.filter.groupIndex   = k_smallGroup;
        circleShapeDef.filter.categoryBits = k_circleCategory;
        circleShapeDef.filter.maskBits     = k_circleMask;

        b2BodyDef circleBodyDef;
        circleBodyDef.type = b2_dynamicBody;
        circleBodyDef.position.Set(5.0f, 2.0f);

        b2Body* body5 = m_world->CreateBody(&circleBodyDef);
        body5->CreateFixture(&circleShapeDef);

        // Large circle
        circle.m_radius *= 2.0f;
        circleShapeDef.filter.groupIndex = k_largeGroup;
        circleBodyDef.position.Set(5.0f, 6.0f);

        b2Body* body6 = m_world->CreateBody(&circleBodyDef);
        body6->CreateFixture(&circleShapeDef);
    }

    static Test* Create() { return new CollisionFiltering; }
};

static int testIndex = RegisterTest("Examples", "Collision Filtering", CollisionFiltering::Create);
